Theoretical infrared spectra of biphenyl, terphenyls and tetraphenyls for astrophysical purposes
Résumé
The infrared spectra of biphenyl, terphenyls, tetraphenyls and of their singly charged positive ions are 23 calculated within the density functional theory framework. This is a resource to aid in searching for what 24 could be abundant species in some regions of carbon star envelopes. These calculations show that there 25 exists a combination of four sets of infrared bands that is unique to these phenyls. Observation of these 26 bands in the envelopes of carbon stars would confirm the importance of polyphenyls in the processes 27 leading to the formation of larger PAHs.